Bin level detection with light intensity sensing

ABSTRACT

An assembly has a bin level detection system having at least one sensor positioned to receive radiation reflected off any material deposited in a bin and to determine an intensity of the reflected radiation. The intensity corresponds to an amount or level of shredded material deposited in the bin. The system may detect radiation from one or more emitters, or, alternatively, detect ambient light entering the bin via a window. A level indicator system may also be provided to indicate the amount of material deposited in the bin, including if the bin is full. The assembly may comprise a shredder and a shredder housing.

RELATED APPLICATION

This application is a divisional of and claims priority to U.S. patentapplication Ser. No. 12/184,631, filed Aug. 1, 2008, which is herebyincorporated by reference in its entirety.

BACKGROUND

1. Field of Invention

The present invention is generally related to an assembly with a bin forreceiving materials, such as a shredder. In particular, the apparatuscomprises a bin level detection system for determining an amount ofmaterial deposited in the bin using reflected radiation.

2. Description of Related Art

Shredders are well known devices for shredding or destroying articlessuch as paper, CDs, DVDs, credit cards, and the like. An example of sucha shredder may be found, for example, in U.S. Pat. No. 7,040,559, whichis herein incorporated by reference in its entirety.

A common type of shredder has a shredder mechanism including a series ofcutter elements contained within a shredder housing that is removablymounted atop a container. The shredded articles are fed into an inputopening and discharged downwardly through a discharge opening into thecontainer.

Conventional full bin indicators for shredder apparatuses typicallyinclude an electronic component in order to detect and/or alert a userthat the bin is full. One such device utilizes an infrared signal thatrecognizes the accumulation of bin contents when a beam is interrupted.Another device involves a mechanical flap that actuates an electronicswitch when the bin has reached capacity.

Because of the generally smaller detector and emitter/transmitter area,full bin indicators having electronic components including beams mayhave problems. For example, systems using beams are prone to dust andstatic malfunctions. Dust may collect on the emitter or transmitter headand may eventually cause the machine to malfunction and falsely triggera signal for a bin full of shredded articles. Stray shredded articlescould also attach themselves to the transmitter or detector due tostatic charges that may build up inside the shredder and trigger asimilar condition. Alternately, mechanical bin full systems may haveissues with shredded articles building up on or around the switchthereby causing “bird-nesting” of shredded materials below the cutters.

SUMMARY

A bin level detection system sensing light intensity in accordance withone or more embodiments of the present invention provides acost-effective way of alerting a user when a shredder bin is nearing orhas substantially reached its capacity for holding shredded particles.

One aspect of the invention provides an assembly including a bin forreceiving material and a bin level detection system. The bin leveldetection system has at least one sensor positioned to receive radiationreflected off any material deposited in the bin and determine anintensity of the reflected radiation. The intensity detected by the atleast one sensor corresponds to an amount of material deposited in thebin.

In an embodiment, the assembly comprises a shredder having a shredderhousing having a shredder mechanism mounted therein. The shredderhousing is provided on the bin and includes an input opening forreceiving materials to be shredded and an output opening for depositingshredded material into the bin.

Another aspect of the invention provides a method for operating ashredder. The shredder has a bin for receiving shredded material and ashredder housing having a shredder mechanism mounted therein. Theshredder housing is provided on the bin and includes an input openingfor receiving material to be shredded and an output opening fordepositing shredded material into the bin. A bin level detection systemis also provided with the shredder and has at least one sensorpositioned to receive radiation reflected off any shredded materialdeposited in the bin. The method includes: detecting the reflectedradiation with the sensor and determining an intensity of the reflectedradiation. The intensity detected by the sensor corresponds to an amountof shredded material deposited in the bin.

Yet another aspect of the invention provides a bin level detectionsystem for a shredder. The shredder includes a shredder housing having ashredder mechanism mounted therein, as well as an input opening on anupper side for receiving materials to be shredded and an output openingon a lower side for depositing shredded material into a bin. The binlevel detection system includes a plurality of sensors positioned on thelower side of the shredder housing to emit and detect radiation suchthat the radiation that is emitted is reflected off any shreddedmaterials deposited in the bin. The plurality of sensors receives theradiation reflected off any shredded material to determine an intensityof the reflected radiation. The intensity corresponds to an amount ofshredded material deposited in the bin. The system also includes a levelindicator system provided on the shredder housing to indicate to a userof the shredder the amount of shredded material deposited in the bin.

Other objects, features, and advantages of the present invention willbecome apparent from the following detailed description, theaccompanying drawings, and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top perspective view of a shredder apparatus constructed inaccordance with an embodiment of the present invention;

FIG. 2 is a detailed perspective view of a lower side of a shredderhousing of the shredder apparatus of FIG. 1 with a bin level detectionsystem for detecting ambient light in accordance with an embodiment ofthe present invention;

FIG. 3 is a detailed view of a sensor of the bin level detection systemin accordance with an embodiment of the present invention;

FIG. 4 is a cross-sectional view of the shredder of FIG. 1 illustratingthe detection of ambient light in accordance with an embodiment of thepresent invention;

FIG. 5 is a cross-sectional view of the shredder of FIG. 1 illustratingthe detection of shredded particles therein using ambient light inaccordance with an embodiment of the present invention;

FIG. 6 shows a circuit used to detect ambient light as shown in FIGS. 4and 5 in accordance with an embodiment of the present invention;

FIG. 7 is a detailed perspective view of a lower side of a shredderhousing of a shredder apparatus with a bin level detection system fordetecting emitted light in accordance with an embodiment of the presentinvention;

FIG. 8 is a cross-sectional view of the shredder of FIG. 7 illustratingthe detection of emitted light in accordance with an embodiment of thepresent invention;

FIG. 9 is a cross-sectional view of the shredder of FIG. 7 illustratingthe detection of shredded particles therein using emitted light inaccordance with an embodiment of the present invention;

FIG. 10 illustrates a top perspective view of a shredder apparatus witha bin level detection system having a sensor operable to detect thepresence of article(s) to be shredded by the shredder in accordance withan embodiment of the present invention;

FIG. 11 shows a circuit which may be used to detect emitted light usingan emitter and receiver as shown in FIGS. 8 and 9 in accordance with anembodiment of the present invention, and

FIG. 12 shows a circuit which may be used to detect emitted light usinga single device as an emitter and receiver in accordance with anembodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

The following embodiments are described with reference to the drawingsand are not to be limiting in their scope in any manner.

FIG. 1 shows a view of a shredder apparatus 10 constructed in accordancewith an embodiment of the present invention. The shredder 10 is designedto destroy or shred articles such as paper, paper products, CDs, DVDs,credit cards, and other objects. In an embodiment, the shredder 10 maycomprise wheels (not shown) to assist in moving the shredder 10. Theshredder 10 comprises a shredder housing 12 that sits on top of acontainer 18, for example. The shredder housing 12 comprises at leastone input opening 14 on an upper side 22 (or upper wall or top side ortop wall) of the housing 12 for receiving materials to be shredded. Theinput opening 14 extends in a lateral direction, and it also oftenreferred to as a throat. The input opening or throat 14 may extendgenerally parallel to and above a shredder mechanism 20 (describedbelow). The input opening or throat 14 may be relatively narrow, so asto prevent overly thick items, such as large stacks of documents, frombeing fed into therein. However, the throat 14 may have anyconfiguration. In an embodiment, an additional or second input opening14 a may be provided in shredder housing 12. For example, input opening14 may be provided to receive paper, paper products, and other items,while second input opening 14 a may be provided to receive objects suchas CDs and DVDs. Shredder housing 12 also comprises an output opening 16on a lower side 24 (or bottom side or bottom wall or underside or binside). Generally speaking, the shredder 10 may have any suitableconstruction or configuration and the illustrated embodiments providedherein are not intended to be limiting in any way. In addition, the term“shredder” or “shredder apparatus,” used interchangeably throughout thisspecification, are not intended to the limited to devices that literally“shred” documents and articles, but instead intended to cover any devicethat destroys documents and articles in a manner that leaves suchdocuments and articles illegible and/or useless.

The shredder 10 also comprises a shredder mechanism 20 (shown generallyin FIG. 2) in the shredder housing 12. When articles are inserted intothe at least one input opening or throat 14, 14 a, they are directedtoward and into shredder mechanism 20. “Shredder mechanism” is a genericstructural term to denote a device that destroys articles using at leastone cutter element. Destroying may be done in any particular way.Shredder mechanism 20 may include a drive system (not shown) with atleast one motor, such as an electrically powered motor, and a pluralityof cutter elements 21. The cutter elements 21 are mounted on a pair ofparallel mounting shafts (not shown). The motor operates usingelectrical power to rotatably drive first and second rotatable shafts ofthe shredder mechanism 20 and their corresponding cutter elements 21through a conventional transmission (not shown) so that the cutterelements 21 shred or destroy materials or articles fed therein, and,subsequently, deposit the shredded materials into opening 19 ofcontainer 18 via the output opening 16. The shredder mechanism 20 mayalso include a sub-frame for mounting the shafts, motor, andtransmission. The drive system may have any number of motors and mayinclude one or more transmissions. Also, the plurality of cutterelements 21 are mounted on the first and second rotatable, parallelshafts in any suitable manner. For example, in an embodiment, the cutterelements 21 are rotated in an interleaving relationship for shreddingpaper sheets and other articles fed therein. In an embodiment, thecutter elements 21 may be provided in a stacked relationship.Furthermore, other devices such as a cooling fan (not shown) for coolingthe motor or one or more vents 36 for releasing heated air therethroughused in cooperation with the shredder mechanism 20 may be provided in oron shredder housing 12. The operation and construction of such ashredder mechanism 20 is well known and need not be discussed herein indetail. As such, the at least one input opening or throat 14 isconfigured to receive materials inserted therein to feed such materialsthrough the shredder mechanism 20 and to deposit or eject the shreddedmaterials through output opening 16.

Shredder housing 12 is configured to be seated above or upon thecontainer 18. As shown in FIG. 2, shredder housing 12 may comprise adetachable paper shredder mechanism. That is, in an embodiment, theshredder housing 12 may be removed in relation to the container 18 toease or assist in emptying the container 18 of shredded materials. In anembodiment, shredder housing 12 comprises a lip 28 or other structuralarrangement that corresponds in size and shape with a top edge 30 of thecontainer 18. However, a complementary fit is not a requirement of thepresent invention. The container 18 receives paper or articles that areshredded by the shredder 10 within its opening 19. More specifically,after inserting materials into input opening 14 for shredding by cutterelements 21, the shredded materials or articles are deposited from theoutput opening 16 on the lower side 24 of the shredder housing 12 intothe opening 19 of container 18. The container 18 may be a waste bin, forexample.

Alternatively, in an embodiment, the shredder housing 12 and bin 18 maybe an integral component. For example, shredded materials may be removedvia a door (not shown) located on the container 18 and/or the shredderhousing 12. In an embodiment, the container 18 may be positioned in aframe beneath the shredder housing 12. For example, the frame may beused to support the shredder housing 12 as well as comprise a containerreceiving space so that the container 18 may be removed therefrom. Forexample, in an embodiment, a container 18 may be provided to slide likea drawer with respect to a frame, be hingedly mounted to a frame, orcomprise a step or pedal device to assist in pulling or removing ittherefrom. Container 18 may comprise an opening or recess (not shown) tofacilitate a user's ability to grasp the bin, and thus provide an areafor the user to easily grasp to separate the container 18 from theshredder housing 12, thereby providing access to shredded materials. Thecontainer 18 may be substantially or entirely removed from being in anoperative condition with shredder housing 12 in order to empty shreddedmaterials such as chips or strips (i.e., waste or trash) locatedtherein. In an embodiment, the container or bin 18 may comprise one ormore access openings (not shown) to allow for the deposit of articlestherein.

At least one window 26 may be provided in one or more walls of thecontainer 18. In an embodiment, the window 26 may be substantiallytranslucent or transparent or, alternatively, comprise a through opening25. The at least one window 26 permits ambient light constitutingradiation to enter the bin 18. Window 26 may also allow a user to viewthe contents within the container 18. As shown in the embodiment of FIG.1, the opening 25 or window 26 may be provided substantially along thelength of a side of the container 18 so as to permit light to bedirected into and toward the container's bottom 19 a. The larger surfacearea of the opening 25 or window 26 allows ambient light to enter from aplurality of directions, even if a part of it is substantially blockedby shredded materials, for example. As further described with referenceto FIGS. 4 and 5, the radiation received through window 26 is reflectedoff of any shredded material or particles deposited within the bin 18and detected by a bin level detection system 32 to determine an amountor level of shredded material deposited therein.

Generally it should be noted that the terms “container,” “waste bin,”and “bin” are defined as devices for receiving shredded materialsdischarged from the output opening 16 of the shredder mechanism 20, andsuch terms are used interchangeably throughout this specification.However, such terms should not be limiting. Container or bin 18 may haveany suitable construction or configuration.

Typically, the power supply to the shredder 10 will be a standard powercord with a plug (not shown) on its end that plugs into a standard ACoutlet. Also, a control panel may be provided for use with the shredder10. Generally, the use of a control panel is known in the art. As shownin FIG. 1, a power switch 100 or a plurality of switches may be providedto control operation of the shredder 10. The power switch 100 may beprovided on the upper side 22 of the shredder housing 12, for example,or anywhere else on the shredder 10. Movement of the manually engageableportion of switch 100 moves the switch module between states. Switchesare generally known in the art and will not be described in detailherein. The switch 100 includes a switch module (not shown) thatconnects the motor to the power supply. This connection may be direct orindirect, such as via a controller. The term “controller” is used todefine a device or microcontroller having a central processing unit(CPU) and input/output devices that are used to monitor parameters fromdevices that at operatively coupled to the controller. As is generallyknown in the art, the controller may optionally include any number ofstorage media such as memory or storage for monitoring or controllingthe sensors coupled to the controller. As described in the embodiment ofFIG. 10 below, the controller may be used selectively enable theoperation of the shredder mechanism 20 based on the detection of thepresence of at least one article (e.g., paper) in the throat 14 by anactivation sensor 60 and/or the amount or level of shredded materials inthe bin 18.

Generally, the construction and operation of the switch 100 andcontroller for controlling the motor are well known and any constructionfor these may be used. For example, a touch screen switch, membraneswitch, or toggle switch are other examples of switches that may beused. Switch 100 may be a sliding switch, a rotary switch, or a rockerswitch. Also, the switch 100 may be of the push switch type that issimply depressed to cycle the controller through a plurality ofconditions. Also, the switch may have distinct positions correspondingto on/off/idle/reverse, and these conditions may be states selected inthe controller by the operation of the switch. Any of the conditions(e.g., power on, idle, power off) could also be signaled by lights, on adisplay screen such as an LCD screen, or otherwise.

Shredder 10 also includes a bin level detection system 32. In anembodiment, bin level detection system 32 comprises at least one sensor34 positioned to receive radiation reflected off any shredded materialdeposited in the bin. As shown in FIG. 2 and in detail in FIG. 3, thesensor 34 may be provided within the shredder housing 12. Specifically,the at least one sensor 34 may be mounted within at least one opening orarea in the lower side 26 of the shredder housing 12. The at least onesensor 34 is covered or enclosed via sensor window 38 located in the atleast one opening or area in the lower side 26 of the housing 12. Thesensor window 38 may comprise a translucent or transparent member forallowing reflected radiation to pass therethrough while still preventingthe inclusion of dust and particles discharged from the shreddermechanism 20 via output opening 16 and into the opening or area adjacentthe sensor 34. In some embodiments, the at least one sensor 34 may beprovided on a lower side 26 or bottom wall of the shredder housing 12,and may protrude slightly therefrom. Nonetheless, the area for andmethod of mounting the sensor 34 should not be limiting.

The at least one sensor 34 is configured to determine an intensity ofthe reflected radiation it receives. The intensity of the reflectedradiation received by the sensor 34 corresponds to an amount of shreddedmaterial deposited in the bin 18. The sensor 34 may be any type ofsensor for detecting intensity of reflected radiation. One known exampleof this type of sensor may include, but should not be limited to,photodetectors or photoconductors.

The bin level detection system 32 of FIG. 2 is used for detectingambient light received through opening 25 or window 26. FIGS. 4 and 5illustrate cross-sectional views of the shredder 10 of FIG. 1 showingthe method of using the bin level detection system 32 to detect ambientradiation or light 40 entering the bin 18 in accordance with anembodiment of the present invention. When the shredder housing 12 isatop the bin 18 and the bin 18 is empty, as shown in FIG. 4, ambientlight 40 may enter through opening 25 or window 26. Ambient light 40 isdeflected off of the bottom 19 a of the container 18 and the reflectedradiation 40 a is received by sensor 34. The bin level detection system32 then detects the reflected radiation 40 a with the sensor 34, anddetermines an intensity of the reflected radiation 40 a.

As the bin 18 becomes full of shredded paper 42 and/or other materials,the contents will pile on the bottom 19 a of the container 18 and beginfilling it. The ambient radiation or light 40 enters through opening 25or window 26 and is deflected off of substantially the top of theshredded materials 42, as shown in FIG. 5. The reflected radiation 40 ais then received by the at least one sensor 34. Again, the bin leveldetection system 32 then detects the reflected radiation 40 a using atleast one sensor 34, and determines an intensity of the reflectedradiation 40 a.

As previously noted, the intensity of the reflected radiation receivedby the sensor 34 corresponds to an amount of shredded material depositedin the bin 18. In some embodiments, the shredder 10 may use any sort ofcircuitry, software, logic, or a combination thereof to determine theintensity readings of the reflected radiation. For example, in anembodiment, the controller comprises logic which determines any changein the detected level of intensity of the ambient light 40. Thus, if adecrease or an increase in intensity of the ambient light 40 isdetermined, an increase or a decrease in the amount of shreddedmaterials in the bin 18 is detected. For example, when usingphotodetectors as sensors 34 to receive reflected radiation 40 a ofambient light 40, a change in intensity is indirectly proportional tothe amount of shredded materials in the bin. Specifically, a decrease inthe intensity of the reflected radiation corresponds to an increase inthe amount of shredded material deposited in the bin. In contrast, asshown in FIG. 5, an increase in the intensity of the reflected radiationcorresponds to a decrease in the amount of shredded material depositedin the bin.

For example, the bin detection system 32 may comprise an ambient lightlevel detection circuit 62 as illustrated in FIG. 6. The circuit 62 maycomprise one or more light sensitive elements such as CdS cell 64 forsensing the reflected radiation 40 a or light beams of ambient light 40.The CdS cell 64 is provided in a voltage divider circuit connected toresister R1 between voltage supply Vcc and circuit ground. The circuit62 may also comprise an amplifier circuit for detecting small changes involtage across resistor R1. As shown in FIG. 6, the amplifier circuitmay be implemented in common source configuration with an n-channelmetal-oxide-semiconductor field-effect transistor (NMOS) and resistorR2. The CdS cell is a light sensitive resistor; thus, if the intensityof the reflected radiation 40 a of ambient light 40 is detected as beinglow or decreasing, the resistance of the CdS cell 64 will be high ascompared to the resistance of the resistor R1. The voltage at thejunction of the CdS cell 64 and resistor R1 will increase withincreasing light intensity. On the other hand, if the intensity of thereflected radiation 40 a increases, the resistance of the CdS cell 64becomes relatively low as compared to the resistance value of theresistor R1, and the voltage at their junction will decrease withdecreasing light intensity. Since the junction of the CdS Cell 64 andresistor R1 lie on the same node as the gate of the NMOS and thejunction of resistor R3 and capacitor C1, the voltage across all theaforementioned junctions will be the same. In low light situation theCdS cell 64 will have a high resistance which will induce a very smallvoltage across R1, not enough to turn on the NMOS. In the instantsituation, the output AN0 of the amplifier will be at a high voltagelevel as determined by the value of resistor R2. However, as theintensity of the reflected radiation increases the resistance of the CdScell 64, it causes a rise in the voltage across resistor R1, turning onthe NMOS. As the voltage at the gate of the NMOS increases it causes areciprocal effect on the AN0 voltage.

In order to ensure that sudden fluctuations in light intensity do nottrigger the detection circuit 62, a stabilizing capacitor C1 may be usedat the gate of the NMOS to prevent rapid fluctuations in gate voltage.As shown in FIG. 6, a resistor R3 may also be implemented in a currentdivider configuration in conjunction with the CdS cell 64 to adjust theresistance of the voltage divider between the CdS cell 64 and resistorR1.

In addition, the controller may use logic and calculations to compensatefor shadows, changes in lighting, or other known events that may occurthat may affect the amount of ambient light 40 received through opening25 or window 26 and that is reflected and/or detected by the at leastone sensor 34.

Referring back to FIG. 1, the bin level detection system 32 may comprisea level indicator system 54. Level indicator system 54 may include anynumber of devices for alerting the user that the bin 18 is nearly orsubstantially full of shredded materials. For example, any number ofaudible signals, visual signals, or a combination thereof may be used asindication devices. An example of a visual signal may be provided in theform of a red warning light, which may be emitted from an LED, forexample. Level indicator system 54 may be provided on the upper side 22of the shredder housing 12 to indicate to a user of the shredder 10 theamount of shredded material deposited in the bin 18.

In the embodiment shown in FIG. 1, the level indicator system 54 is aprogressive indication system comprising a plurality of lights whichcorrespond to the amount of shredded material in the bin 18. Forexample, the progressive indication system may comprise a series ofindicators in the form of lights to indicate the accumulation or levelof shredded materials such as 42 in the bin 18. The system 54 mayinclude a green light, a plurality of yellow lights, and a red light.The green light may indicate that the bin 18 is substantially empty. Theyellow lights could provide a progressive indication of the amount ofshredded materials accumulating in the bin 18. The red light may be usedat the end of the sequence of lights to indicate that the capacity ofbin 18 is substantially full. In some embodiments, a plurality of lights(in any color) could be used to progressively indicate the amount ofshredded materials in the bin 18. In an embodiment, the level indicatorsystem 54 may be provided on a screen such as a digital or LCD screen.In some embodiments, letters or words such as “BIN FULL” may be shown asindicators. Other visual indicators such as a bar graph that increasesas the amount of shredded materials in the bin increases, or a “fuelgauge,” i.e., a dial with a pivoting needle moving progressively betweenzero and maximum desired amount of shredded materials in the bin, mayalso be used. Alternatively, other ways of getting a user's attentionmay be used, such as flashing one or more of the lights in the sequence,to indicate that the bin 18 is substantially full.

In an embodiment, audible signals may be used with the level indicatorsystem 54. Examples of audible signals include, but are not limited to,beeping, buzzing, and/or any other type of signal that will audiblyalert the user that the bin 18 is substantially full of shreddedmaterials. Similarly, the aforementioned indicators of the progressiveindicator system may be in the form of audible signals, rather thanvisual signals or lights. For example, like the yellow lights describedabove, several types of audible signals may be used to indicate theamount of materials in the bin. For example, when a user inserts anarticle into the throat 14 of the shredder 10, an audible signal may beheard to indicate the level or amount of shredded materials in the bin18. The level indicator system 54 may provide audible signals in theform of spoken words such as “bin full.” Any of the above noted audiblesignals gives the user the opportunity to remove shredded materials orparticles from the inside 19 of the bin 18.

The above noted audible and visible alert features of the levelindicator system 54 may be used in lieu of or in conjunction withcutting off power to the shredder mechanism 20 upon detecting that thebin full level has been substantially reached or exceeded. In addition,the level indicator system 54 may be used in cooperation with one ormore activation sensors 60, as described below with respect to FIG. 10.However, it should be noted that in some embodiments the level indicatorsystem 54 need not be provided on the housing 12 (e.g., as shown in theillustration of the shredder of FIG. 10), and/or may be provided on anynumber of places on the shredder 10, or not provided at all.

Though the embodiment in FIGS. 1-5 describes the at least one sensor 34receiving radiation in the form of ambient light 40, the type ofradiation received by the at least one sensor 34 should not be limiting.For example, in an embodiment, the radiation received by one or moresensors may include light in the visible spectrum, infrared radiation,and/or ultraviolet radiation. Such forms of radiation may be provided byinternal emitters in the container 18, for example.

FIG. 7 illustrates a bin level detection system 58 for detecting emittedlight in accordance with an embodiment of the present invention. Asshown, the system 58 comprises at least one emitter 48 positioned toemit the radiation downwardly into the bin 18. The system 58 alsocomprises at least one receiver 44 to receive the radiation reflectedoff any shredded material deposited in the bin. In some embodiments, asshown in FIG. 7, a plurality of receivers 44 and a plurality of emitters48 are mounted on the bottom wall of the lower side 26 of the shredderhousing 12. The plurality of receivers 44 and/or plurality of emitters48 may be arranged in a spaced apart relation. The radiation emitted bythe at least one emitter 48 may include light in the visible spectrum,infrared radiation, and/or ultraviolet radiation. Similarly, theradiation received by the at least one receiver 44 may include light inthe visible spectrum, infrared radiation, and/or ultraviolet radiation.

In some embodiments, the one or more emitters mounted to the lower side26 of housing 12 are flush with the bottom wall of the lower side 26, asindicated by 48 a. In some embodiments, one or more emitters 48 areprovided on structures 46 extending downwardly from the bottom wall orlower side 26. In an embodiment, the structures 46 extending downwardlyfrom the bottom wall comprise springs or other resilient structures.

In a similar manner to the sensor 34 as shown in FIG. 2, the one or morereceivers 44 may be provided within the shredder housing 12.Specifically, in an embodiment, the one or more receivers 44 may bemounted within at least one opening or area in the lower side 26 of theshredder housing 12. The one or more receivers 44 are covered orenclosed via sensor window 50 located in the one or more openings orareas in the lower side 26 of the housing 12 for receiving the receivers44. The sensor window 50 may comprise a translucent or transparentmember for allowing reflected radiation to pass therethrough while stillpreventing the inclusion of dust and particles discharged from theshredder mechanism 20 via output opening 16 and into the opening or areaadjacent the receivers 44. In some embodiments, the one or morereceivers 44 may be provided on a lower side 26 or bottom wall of theshredder housing 12, and may protrude slightly therefrom. Also, in anembodiment, one or more receivers 44 may be provided on one or more sidewalls of the container 18, such as near lip 30, for example. An exampleof the mounting of such a receiver 44 is represented in FIG. 7 byreceiver 44 a. Nonetheless, it should be noted that the area for andmethod of mounting the receivers 44, 44 a should not be limiting.

Alternatively, the emitters 48 may be mounted on one or more side wallsof the container 18 or in any other manner so as to emit radiation intothe container 18, as represented by sensors 48 b in FIG. 7. The mountinglocation of the emitters 48, 48 a, and/or 48 b should not be limiting.

The one or more receivers 44 are configured to determine an intensity ofthe received reflected radiation from the one or more emitters 48. Theintensity of the reflected radiation received by a receiver 44corresponds to an amount of shredded material deposited in the bin 18.The receivers 44 may be any type of sensor for detecting intensity ofreflected radiation. One known example of this type of sensor mayinclude, but should not be limited to, photodetectors orphotoconductors.

The bin level detection system 58 of FIG. 7 is used for detectingemitted light from emitters 48. FIGS. 8 and 9 illustrate cross-sectionalviews of the shredder 10 showing the method of using the bin leveldetection system 58 to detect emitted radiation 52 directed downwardlyinto the bin 18 in accordance with an embodiment of the presentinvention. When the shredder housing 12 is atop the bin 18 and the bin18 is empty, as shown in FIG. 8, emitted light 52 from the one or moreemitters 48 may be directed toward the bottom 19 a of the bin 18.Emitted light 52 may be deflected off of the sides and/or bottom 19 a ofthe container 18 and the reflected radiation 52 a is received byreceivers 44. The bin level detection system 58 then detects thereflected radiation 52 a with the receivers 44, and determines anintensity of the reflected radiation 52 a.

As the bin 18 becomes full of shredded paper 42 and/or other materials,the contents will pile on the bottom 19 a of the container 18 and beginfilling it. The emitted radiation 52 or light is directed downwardlyinto the bin 18 and is deflected off of substantially the top of theshredded materials 42, as shown in FIG. 9. The reflected radiation 52 ais then received by the at least one receiver 44. Again, the bin leveldetection system 58 then detects the reflected radiation 52 a using atleast one receiver 44, and determines an intensity of the reflectedradiation 52 a.

As noted above, the intensity of the reflected radiation received by thereceivers 44 corresponds to an amount of shredded material deposited inthe bin 18. The receivers 44 and emitters 48 of the bin level detectionsystem 58 may use any sort of circuitry, software, logic, or combinationthereof to determine the intensity readings of the reflected radiationin a similar manner as described above (e.g., indirectly proportional).In some embodiments, the emitters 48 of the system 58 may comprise LEDs.

When using emitted light, such as emitters 48, the receivers 44 candetect the presence or absence of shredded materials in the bin 18 in asimilar manner as described above. However, the circuitry and/or logicto determine the intensity readings of the reflected radiation ofemitted light may, in some embodiments, act in a different manner.Specifically, the change in intensity of emitted light may be directlyproportional to the amount of shredded materials in the bin. That is, ifa decrease or an increase in intensity is determined, a decrease or anincrease, respectively, in the amount of shredded materials in the bin18 is detected. Specifically, when using emitting and receiving sensingdevices 48 and 44, a decrease in the intensity of the reflectedradiation 52 a of the emitted light 52 corresponds to a decrease in theamount of shredded material deposited in the bin. In contrast, anincrease in the intensity of the reflected radiation detected by theLEDs corresponds to an increase in the amount of shredded materialdeposited in the bin. For example, as shown in FIG. 9, as the emittedlight 52 from the emitters 48 is reflected off of the shredded material42, the intensity of the reflected light 52 a increases, thus indicatingan increase in the amount of shredded material in the bin 18. However,the emitters 48 and receivers 44 may alternately determine the amount ofshredded materials in an indirectly proportional manner in relation tothe intensity of the reflected radiation, as described above withreference to FIGS. 4 and 5.

For example, the bin detection system 32 may comprise an emittedradiation level detection circuit 66 as illustrated in FIG. 11. Thecircuit 66 may comprise LEDs D1 and D3 which act as an optional lightsources or emitters such as emitters 48, 48 a, or 48 b. Reflected lightor radiation is received by the sensor D2 and produces a current. As theintensity of the radiation increases, the current increases as well. Asthis current flows through resistor R2, a voltage is produced. Thevoltage produced is directly proportional to the current (as lightincreases, current increases, thus, voltage increases). In thisparticular embodiment, the voltage produced across resistor R2 isamplified by the amplifier U1. The illustrated amplifier section is notrequired; however, the amplifier section of circuit 66 may be used toachieve a more optimal signal. Resistors R3 and R4 are used to set thegain of the amplifier U1. The output signal is then directed to anappropriate or selected logic circuit (not shown), such as amicrocontroller, amplifier circuit, comparator, etc.

In some embodiments, the emitters 48 and receivers 44 may be provided asa single sensor. That is, at least one sensor for emitting and receivingradiation may be provided on the bottom wall of the lower side 26 of thehousing 12. For example, in an embodiment, the at least one sensorcomprises a single device that alternates between operating in a forwardbias mode to emit radiation and a reverse bias mode to detect radiation.In some embodiments, the at least one sensor comprises one or more LEDs.In some embodiments, the at least one sensor mounted to the bottom wallis flush with the bottom wall. For example, the emitter 48 a may act aseither an independent emitter or a single device used for emitting anddetecting radiation. In some embodiments where the at least one sensoris a single device (such as an LED), the at least one sensor is providedwithin the shredder housing 12 behind a protective surface, such as asensor window 38 as illustrated in FIG. 2. In this way, the singledevice or LED is less susceptible to false readings or errors due todust and particles, for example. Additionally, using a single devicesuch as an LED provides additional benefits such as cost reduction(e.g., using only a single device), a controllable input, as well as thepotential to provide multiple and/or redundant sensors while stillreducing the costs.

When using LEDs as sensing devices, the LEDs can detect the presence orabsence of shredded materials in the bin 18 in a similar manner asdescribed above. However, the circuitry and/or logic to determine theintensity readings of the reflected radiation used with LEDs may act ina different manner. Specifically, the change in intensity is directlyproportional to the amount of shredded materials in the bin. That is, ifa decrease or an increase in intensity is determined, a decrease or anincrease in the amount of shredded materials in the bin 18 is detected.Specifically, when using LEDs as emitting and receiving sensing devices,a decrease in the intensity of the reflected radiation corresponds to adecrease in the amount of shredded material deposited in the bin, asshown in FIG. 8. In contrast, as illustrated in FIG. 9, an increase inthe intensity of the reflected radiation detected by the LEDscorresponds to an increase in the amount of shredded material depositedin the bin.

For example, the bin detection system 32 may comprise an emittedradiation level detection circuit 68 as illustrated in FIG. 12. Thecircuit 68 of FIG. 12 comprises an LED 70 as a single device foremitting and detecting radiation. The LED 70 is connected across thepins of the microcontroller 72. There is an optional series resistor R1shown with the LED 70 to limit the current through the LED 70. Themicrocontroller 72 is responsible for alternating the bias of the LED 70and reading the analog voltage produced. The microcontroller 72 firstforward biases the LED 70 to turn the light on. After a predeterminedamount of time, the microcontroller 72 may then reverse bias the LED 70to act as a photo diode. After another predetermined amount of time, themicrocontroller reads the voltage across the device. Because there isintrinsic resistance and capacitance in the components, the RC timeconstant of the device allows the single component to detect the lightit produced being reflected towards it.

The bin level detection systems 32 or 58 described herein providedetection devices with a cost-effective way of alerting a user when thebin 18 is nearing or is substantially reached its capacity (i.e., isfull) of shredded material. The systems assist in indicating the amountof shredded material in the bin 18 with improved accuracy over previousmethods. Also, the bin level detection systems 32 or 58 provide feedbackto users showing a measured level of shreds in the bin 18. Reflectedradiation in the form of ambient light or emitted light received by thesensors 34, 44, and/or 48 allows for monitoring of the intensity of theradiation within the bin 18 and indicates via level indicator system 54the amount of shredded materials or fullness of the bin. Sensingreflected radiation using the herein described sensors that areprotected by windows 38 and 50 aid in reducing the sensitivity of thebin level detection system typically associated with the prior art, suchas the collection of dust and stray shreds which could producemalfunctions or false signals. The described systems 32 and 58 accordingto various embodiments of the present invention also improve on priormechanical bin full systems as there are no protruding mechanical parts,thus preventing shredded materials from building up on a switch and/orbird nesting below the cutter elements 21 or output opening 16.

The bin level detection systems 32 or 58 described herein may be usedwith any number of systems or devices known in the art associated withshredders 10. As previously noted, in addition or alternatively toindicator 54 discussed above, an activation sensor 60 may also beprovided on shredder 10. The sensor 60 may communicate with the motor 18to power the shredder mechanism 20 via the controller. Activation sensor60 may be operable to detect the presence of article(s) to be shreddedby the shredder 10. Activation sensor 60 may be placed in, adjacent, ornear the throat 14 or 14 a, as illustrated in FIG. 10. Activation sensor60 may include an infrared sensor or a light emitting diode (LED), forexample. The sensor may detect the presence of an article in throat 14or 14 a. Of course, any such sensor may be used. The illustratedembodiment is not intended to be limiting in any way. The sensor 60provides a signal to the controller which in turn may provide a signalto the motor. Specifically, the controller may control whether power isprovided to the motor so that the shafts may rotate the cutter elements21 and shred the article(s) inserted into throat 14 or 14 a. If the binlevel sensing systems 32 or 58 detect that the bin 18 is full ofshredded materials, however, power will not be provided to the shreddermechanism 20, thereby making the shredder 10 temporarily inoperable,even though the sensor 60 has detected the presence of an article to beshredded. This not only protects the motor 18, but it also provides anadditional feature for preventing jamming of articles in the outputopening 16 or materials getting caught within the cutter elements 21 ofthe shredder mechanism 20.

In some embodiments, the sensors of the bin level detection system 32may be provided to work in cooperation with proximity sensors. Forexample, a proximity or capacitive sensor, acting as a switch thatdetects the presence of a person or thing without requiring physicalcontact, may be provided on shredder housing 12. Such sensors may assistin preventing harm or injury to a user.

In an embodiment, the controller may include logic for compensating forthe decreasing in the intensity of the emitters 48 or sensors 48 a(e.g., such as LED(s) or infrared devices) by calibrating and/orrecalibrating the sensors periodically. Calibrating the emitters 48 orsensors 48 a may assist in preventing false positive signals being sentfrom the controller to the shredder mechanism 20, as well as increasethe life the emitters 48 and/or sensors 48 a. In addition, thecontroller 56 may be used to distinguish between false errors fromambient light 40.

Also, though the bin level detection systems 32 and 58 are describedherein as being associated with a shredder 10, the systems 32 and 58 mayalternatively be used with a variety of other assemblies that include abin for receiving material (e.g., waste can, dumpster, recyclingcontainer, storage container for various goods). For example, in anembodiment, an assembly may comprise a bin such as bin 18 and any of thebin level detection systems as described above, i.e., comprising atleast one sensor positioned to receive radiation reflected off anymaterial deposited in the bin and determine an intensity of thereflected radiation, the intensity corresponding to an amount ofmaterial deposited in the bin.

In various of the illustrated embodiment, the bin level detectionsystems are used to indicate when the bin becomes full in an environmentwhere use of the bin causes it to fill with material. However, accordingto alternative embodiments of the present invention, the bin leveldetection systems are used to indicate when a bin becomes empty, forexample in an assembly in which the amount of material in the bindecreases with use (e.g., a storage bin that automatically feeds itsstored material for use; a candy or other food dispenser having astorage bin; a plastic bead storage bin attached to an automatic feedassembly for feeding the plastic beads into a plastic mold; etc.).

In some embodiments, any of the sensors 34, receivers 44, 44 a, emitters48, 48 a, 48 b, or windows 26, 38, or 50 may be provided in any numberof locations on or in the assembly or the shredder 10. For example, suchlocations may include a lower side 26 or bottom wall of the shredderhousing 12, one or more side walls of the bin 18, on the bin 18 adjacentthe lip 30, or any other location that allows for emitting and/ordetecting radiation that is reflected off of material in the bin 18.Nonetheless, the areas for and method of mounting the noted devicesshould not be limiting.

Additionally, it should be noted that the directions of receivingambient light or emitted light should not be limited to thoseillustrated in FIGS. 4-5 and/or FIGS. 8-9. Generally, the radiation orlight may be received and/or emitted in any number of directions. Theradiation may also be deflected in any number of ways within thecontainer 18 and the noted illustrations should not be limiting.

While the principles of the invention have been made clear in theillustrative embodiments set forth above, it will be apparent to thoseskilled in the art that various modifications may be made to thestructure, arrangement, proportion, elements, materials, and componentsused in the practice of the invention.

It will thus be seen that the objects of this invention have been fullyand effectively accomplished. It will be realized, however, that theforegoing preferred specific embodiments have been shown and describedfor the purpose of illustrating the functional and structural principlesof this invention and are subject to change without departure from suchprinciples. Therefore, this invention includes all modificationsencompassed within the spirit and scope of the following claims.

What is claimed is:
 1. A method for operating an assembly, the assemblycomprising a bin for receiving material and a bin level detection systemcomprising at least one sensor positioned to receive radiation reflectedoff any material deposited in the bin, the method comprising: detectingthe reflected radiation with the sensor, and determining an intensity ofthe reflected radiation, wherein the intensity detected by the sensorcorresponds to an amount of shredded material deposited in the bin.
 2. Amethod for operating an assembly according to claim 1, wherein adecrease in the intensity of the reflected radiation corresponds to anincrease in the amount of material deposited in the bin.
 3. A method foroperating an assembly according to claim 1, wherein a decrease in theintensity of the reflected radiation corresponds to a decrease in theamount of material deposited in the bin.
 4. A method for operating anassembly according to claim 1, wherein an increase in the intensity ofthe reflected radiation corresponds to a decrease in the amount ofmaterial deposited in the bin.
 5. A method for operating an assemblyaccording to claim 1, wherein an increase in the intensity of thereflected radiation corresponds to an increase in the amount of materialdeposited in the bin.
 6. A method for operating an assembly according toclaim 1, wherein the assembly further comprises a shredder, the shreddercomprising a shredder housing having a shredder mechanism mountedtherein, the shredder housing being connected to the bin and comprisingan input opening for receiving materials to be shredded and an outputopening for depositing shredded material into the bin, wherein the binreceives the shredded material, and wherein the at least one sensorreceives radiation reflected off any shredded material deposited in thebin.
 7. A shredder comprising: a shredder housing having a shreddermechanism mounted therein, the shredder housing comprising an inputopening for receiving materials to be shredded and an output opening fordepositing shredded material therefrom, and a bin level detection systemcomprising: at least one sensor positioned to emit and detect radiationreflected off any shredded materials accumulated below the outputopening and determine an intensity of the reflected radiation, theintensity corresponding to an amount of shredded material disposed belowthe output opening, and a level indicator system provided on theshredder housing to indicate to a user of the shredder the amount ofshredded material disposed below the output opening.
 8. A shredderaccording to claim 7, wherein the level indicator system is aprogressive indicator comprising a plurality of lights which correspondto the amount of shredded material disposed below the lower side.
 9. Ashredder according to claim 7, wherein the level indicator systemincludes a device for alerting the user via signals selected from thegroup of audible signals, visual signals, or a combination of audibleand visual signals.
 10. A shredder according to claim 7, wherein the atleast one sensor is mounted to a bottom wall of the shredder housing.11. A shredder according to claim 7, wherein the at least one sensorcomprises one or more light emitting diodes.
 12. A shredder according toclaim 7, further comprising a bin for receiving shredded materials, theshredder housing being provided on the bin, and wherein the amount ofshredded material disposed below the output opening comprises an amountof shredded material within the bin.
 13. A shredder according to claim7, wherein the at least one sensor is mounted to a side wall of theshredder housing.
 14. An assembly according to claim 7, wherein theinput opening is provided on an upper side of the shredder housing andoutput opening is provided on a lower side of the shredder housing.